mistergarrett

I was checking my tail lights and brake lights and noticed when my parking lights or headlights are switched on both filaments on my brake lights light up. So when my lights are on at night, you cant tell when Im braking. I didnt wanna start a new thread but I've searched for hours and havent found anything like this. Something else that dont bother me to much, when my lights are turned off, i can push my brake pedal and my front parking lights come on as well as the back lighting on my instrument panel. Even when my lights are off the brake pedal lights up both filaments. Anyone ever heard of this?? Or did a previous owner do a hack job on my wiring? BTW if it helps this is on a 89 xtra long cab 3.0 A340H. Feel free to PM or email, Heck if ya wanna call me I'd give ya my number. Can u say desparate. Help please and thank you.

mistergarrett

bump Please.....

4Crawler

iTrader: (3)

Sounds like it could be a missing/bad ground connection at the brake light sockets or the wrong bulb. Why? The brake and parking lights share a dual filament bulb in that socket and that bulb has 3 contacts, one for brake, one for park and a common ground. Lose the ground connection and the parking light current will find a path to ground via the brake light filament (i'e' they both turn on). And when the parking lights are off, the brake lights find a path to ground via the parking lights. Could also be someone installed a single filament (1156) bulb in there instead of the proper 1157 dual filament type.

mistergarrett

Cool. gives me a place to start lookin. I know the blubs are dual filament, checked that first. 1157 or 2057 are the bulbs but its probably the ground. I just thought its wierd that the dash lights and front parking lights shine when the brakes are applied. Thanks a million

mistergarrett

I knew the bulbs were dual filament, but i changed them anyway. I put in 2057's. I even changed the brake light assembly with a 90 22re I have that i know for a fact worked. I did notice that there is wiring for trailer lights. Some of the brake light plugs have 2 wires going in to them. I also found a modual under the dash for a remote start system and splices everywhere under the dash and on the tail light wiring on the back end of the truck. I ve got the whole dash taken apart including the steering colum cover looking for shorts and found none. I guess the only thing left is to cut the black tape off the wiring in the back and un hook the trailer lights. What im getting at, the trailer lights short or not would not explain why the all the parking lights (front and both filaments on the back) and the dash lights lit up with the brake pedal engaged. Any more info would be sooooooo greatly appreciated. Thanks in advance.

4Crawler

iTrader: (3)

Yes, disconnect the trailer wiring adapter and see if anything changes.

mistergarrett

Gonna do it after work tomarrow. I just got everything back together. Will post up when Im done. Thanx

mistergarrett

The trailer light harness was the culprit. After endless cutting of black tape and plastic conduit, I got to the point where I could see all the splices and solderless connectors, I cut all the wires that led to the trailer lights, and like a miracle everything worked like new. No more parking lights or dash lights when I press the brake pedal. And only one filament lights up with the brake pedal pressed. YotaTech strikes again. Thanks 4Crawlwer.

Cordova2013

Bumping a really old thread here, but complying with rules here I searched before starting a new thread. Newbie here also. Just joined! I have an 87 Xtra cab 22R, just picked up. Other than a hole in the timing cover that is being fixed Friday, I have this problem as well. Went out and inspected the rear wiring and yep, it has trailer lights. What do I need to cut to solve the instrument panel lighting up, along with both filaments in the rear, and the parking lights in the front. I dont PLAN to be towing a trailer, but I like having capabilities.. Once I cut the wiring for the trailer lights to solve this problem, how would I go about CORRECTLY wiring in trailer lights? Thanks in advance!

4Crawler

iTrader: (3)

All depends on how the trailer connector is attached and what type it is. Two options are:
1. Remove one wire at a time and see when the problem goes away.
2. Remove/cut all wires and see if the problem goes away. If it does, then connect one at a time and see when it reappears.

Problem is many folks just hook up a 4 wire connector directly:

- http://www.eyer˟˟˟˟ch.com/brake-control-wiring.html

And that can cause problems because if you note, left turn + brake is one wire, right turn + brake is another wire then there are tail lights and ground. This is how trailer tail light work, they are usually pretty simple.

On the Toyota, look at the factory wiring diagram. You'll note the turn signal is one bulb and brake/tail light is a separate dual filament bulb. Tie brake + turn together and you get the idea, you have just shorted two different light bulbs together. Since the brake and tail lights are the same bulb (again 1157 bulb, two filaments and a common connection terminal), turn on the headlights and you have power to the tail (and brake) light bulb and then that connection to the turn signal bulb (via the trailer connector). So if that turn signal is not on, it may be grounded and you can have current flowing through the brake light to ground at the turn signal or some other strange path. In any event, you can imagine just wiring in a few pieces of wire haphazardly between some of the connectors in your tail light assembly and then seeing what happens.

So what you need is a proper trailer wiring adapter. They usually have blocking diodes or similar components inside to combine the various inputs and yet keep them isolated. My '85 had a U-Haul 5-wire converter box installed and it seems to work fairly well. A 5-wire has ground, tail, brake, left turn and right turn inputs and then the above 4 outputs; i.e 5-wires in, 4-wires out.

Only minor issue I have with that U-Haul box is that if I run LED turn signal bulbs (very low current) and I have the headlights on, I'll see the turn indicators on the dash slowly brighten then turn off over 5-10 second interval. I suspect one of the converter diodes has a somewhat high leakage current and with the LED bulbs, that is enough to make the dash indicator light up. If I run regular filament bulbs, no problems as the low resistance of the filament prevents any leakage current from building up enough voltage to light up the turn indicator.

At some point, I want to install a proper relay isolated trailer wiring converter. That way you only use the factory light switches and wires to turn on a relays, then the relays send current to the trailer lights. I also want to add in a connection up front to do the reverse, that is allow a towing vehicle to plug in and operate my tail lights if I need to flat tow the vehicle.

Cordova2013

Hey thanks so much! And yeah, from what I seen last night it was very haphazardly spliced and taped together. I'll disassemble their wiring and return it to factory for now. Shouldn't be towing in the near future. I'll go buy some proper harnesses and install later. Thank you again! Helps tremendously

Terrys87

iTrader: (1)

I got my tail light conversion kit. I do alot of pulling. Its PN# 43315. I get mine at Oriellys. Works great.

Cordova2013

And that will require no splicing so that it won't cause the same problems as I currently have? I do alot of business with oreillys, so that works out great for me! I'll have to pick one up

Terrys87

iTrader: (1)

No slpicing, it is plug and play. It does have an electrical box that I think has some capacitors that need to charge up when you hook up a trailer. The trailer lights wont come on right away sometimes. I have installed 3 of these and they work great. You wont have fast blinking blinkers either like you do when you hook up a trailer. They blink the normal speed like they should. It is about $20-$25 for the wiring kit. Works Great!!!

Cordova2013

Thank you my good sir, I appreciate it much! I'm about to go disassemble the old wiring shortly

Cordova2013

Redneck rigging removed. Spliced and matched all wires to their factory mates. Everything returned to normal with the exception of no brake lights. The previous owner had a wire bridged between the driver side tail light wire (green) and the brake light wire (green w/ white tracer). I cut that wire into and then just took off the excess wire without disassembling the splice. When I realized I had no brake lights I disassembled the splice and rebridged the connection. Magically had brake lights then! But when I turned on my lights, I had a solid light. No tail light, only brake lights with the lights on. Without having the pedal pressed I may add. My question is what do I need to do to make my tail and brake lights function correctly and independently when my lights are on??

Cordova2013

Bump really need some help

Terrys87

iTrader: (1)

I dont know electrical. I have had issues with the wiring rubbing on the transmission. The reverse light connector is located there. Might check and see if that is an issue. There is a brake sensor on the pedal. Is the button stuck in or out. Just trying to givew you some ideas of where else to check. Sounds like a short somewhere.

wyoming9

iTrader: (1)

Someplace you don`t have the wires connected correct

On your 87 Toyota

Your Brake lights are the Green/white wire

Your tail lights are the Green wire

If you have them spliced together all the lights will come on with the brake light switch if that does not happen the brake light circuit is not working.

Why that was done who can say but it is part of the hack job wiring and should be removed.

Then trouble shoot the brake light circuit and figure out why it is not working .

Could be as simple as a fuse a bad switch or a poor ground broken wire

Cordova2013

I'll check fuses, and cut out the old splice and properly repair. Maybe that'll solve it. We're almost done with the timing chain job and then she will be hitting the road